The other car is the crumple zone
Seriously though, crumple zones in cars and trucks aren't the sheet metal on the body.
I'm sure Tesla thought about safety ratings. My guess is the "cyber truck"'s sheet metal will crumple in an accident. A car wreck has a lot more force than some guy swinging a sledgehammer at medium force.
And I think we're all pretty sure that Elon overrode those designers and demanded a design and materials that wouldn't crumple.
There's a big difference to "stands up to parking lot car doors and shopping carts" and assuming that it doesn't crumple in a collision with another vehicle.
aka "What happens when an unstoppable force meets an immovable object?"